COMPOUND-SPECIFIC δD OF LIPIDS: A NEW POTENTIAL TOOL FOR RECONSTRUCTING THE PALEO-CLIMATIC ENVIRONMENT

The compound-specific carbon stable isotopic composition of lipids has been indicated to be a powerful tool for the reconstruction of paleo-climate and paleo-environment.However, its resolution is not high enough to trace the small scale changes in the paleo-climatic variability. Recently, the compound-specific hydrogen isotope ratio (D/H) of lipids, a more sensitive tool for reconstructing paleo-climate and paleo-environment, has been developed due to the application of a new technology of gas chromatography-thermal conversion-isotope ratio mass spectrometry (GC-TC-IRMS). The recent progress of the compound-specific hydrogen isotope ratio in the reconstruction of paleo-climate and paleo-environment was reviewed in this paper. It is indicated that the δD values of individual lipid compounds have a close correlation with the environmental temperature and humidity changes and record the δD values of source water according to the isotopic fractionation and the environmental temperature change. The δD values of terrestrial lipid compounds are higher than those of the aquatic compounds due to the evaporative enrichment of deuterium in the leaf water. Based on the differences between δD values of terrestrial and aquatic compounds, the evapotranspiration of the lake environment and the paleo-humidity could be reconstructed. Therefore, the compound-specific δD value of lipid is a new potential proxy for the reconstruction of paleo-climate and paleo-environment.